diff --git a/css/css.c b/css/css.c
index 8923bdc07..0410f180d 100644
--- a/css/css.c
+++ b/css/css.c
@@ -129,6 +129,7 @@ nserror nscss_create(const content_handler *handler,
 {
 	nscss_content *result;
 	const char *charset = NULL;
+	const char *xnsbase = NULL;
 	lwc_string *charset_value = NULL;
 	union content_msg_data msg_data;
 	nserror error;
@@ -155,9 +156,14 @@ nserror nscss_create(const content_handler *handler,
 		charset = lwc_string_data(charset_value);
 	}
 
+	/* Compute base URL for stylesheet */
+	xnsbase = llcache_handle_get_header(llcache, "X-NS-Base");
+	if (xnsbase == NULL) {
+		xnsbase = nsurl_access(content_get_url(&result->base));
+	}
+
 	error = nscss_create_css_data(&result->data, 
-			nsurl_access(content_get_url(&result->base)),
-			charset, result->base.quirks, 
+			xnsbase, charset, result->base.quirks, 
 			nscss_content_done, result);
 	if (error != NSERROR_OK) {
 		msg_data.error = messages_get("NoMemory");
diff --git a/render/html_css.c b/render/html_css.c
index b98632e61..3eabec419 100644
--- a/render/html_css.c
+++ b/render/html_css.c
@@ -296,7 +296,7 @@ html_stylesheet_from_domnode(html_content *c,
 		return NSERROR_OK;
 	}
 
-	error = html_css_fetcher_add_item(style, &key);
+	error = html_css_fetcher_add_item(style, c->base_url, &key);
 	if (error != NSERROR_OK) {
 		dom_string_unref(style);
 		return error;
diff --git a/render/html_css_fetcher.c b/render/html_css_fetcher.c
index 31e2cba13..9bd3b21a6 100644
--- a/render/html_css_fetcher.c
+++ b/render/html_css_fetcher.c
@@ -37,6 +37,7 @@
 typedef struct html_css_fetcher_item {
 	uint32_t key;
 	dom_string *data;
+	nsurl *base_url;
 
 	struct html_css_fetcher_item *r_next, *r_prev;
 } html_css_fetcher_item;
@@ -142,6 +143,7 @@ static void html_css_fetcher_free(void *ctx)
 
 	nsurl_unref(c->url);
 	if (c->item != NULL) {
+		nsurl_unref(c->item->base_url);
 		dom_string_unref(c->item->data);
 		RING_REMOVE(items, c->item);
 		free(c->item);
@@ -195,7 +197,7 @@ static void html_css_fetcher_poll(lwc_string *scheme)
 			/* Nothing to do */
 			assert(c->locked == false);
 		} else if (c->item != NULL) {
-			char header[64];
+			char header[4096];
 
 			fetch_set_http_code(c->parent_fetch, 200);
 
@@ -221,6 +223,18 @@ static void html_css_fetcher_poll(lwc_string *scheme)
 				html_css_fetcher_send_callback(&msg, c);
 			}
 
+			if (c->aborted == false) {
+				snprintf(header, sizeof header, 
+					"X-NS-Base: %.*s",
+					(int) nsurl_length(c->item->base_url),
+					nsurl_access(c->item->base_url));
+				msg.type = FETCH_HEADER;
+				msg.data.header_or_data.buf = 
+						(const uint8_t *) header;
+				msg.data.header_or_data.len = strlen(header);
+				html_css_fetcher_send_callback(&msg, c);
+			}
+
 			if (c->aborted == false) {
 				msg.type = FETCH_DATA;
 				msg.data.header_or_data.buf = 
@@ -280,7 +294,8 @@ void html_css_fetcher_register(void)
 		html_css_fetcher_finalise);
 }
 
-nserror html_css_fetcher_add_item(dom_string *data, uint32_t *key)
+nserror html_css_fetcher_add_item(dom_string *data, nsurl *base_url,
+		uint32_t *key)
 {
 	html_css_fetcher_item *item = malloc(sizeof(*item));
 
@@ -290,6 +305,7 @@ nserror html_css_fetcher_add_item(dom_string *data, uint32_t *key)
 
 	*key = item->key = current_key++;
 	item->data = dom_string_ref(data);
+	item->base_url = nsurl_ref(base_url);
 
 	RING_INSERT(items, item);
 
diff --git a/render/html_internal.h b/render/html_internal.h
index f92948b0d..90f014307 100644
--- a/render/html_internal.h
+++ b/render/html_internal.h
@@ -268,11 +268,13 @@ nserror html_css_free_stylesheets(html_content *html);
 bool html_css_process_link(html_content *htmlc, dom_node *node);
 bool html_css_update_style(html_content *c, dom_node *style);
 
-nserror html_css_new_selection_context(html_content *c, css_select_ctx **ret_select_ctx);
+nserror html_css_new_selection_context(html_content *c,
+		css_select_ctx **ret_select_ctx);
 
 /* in render/html_css_fetcher.c */
 void html_css_fetcher_register(void);
-nserror html_css_fetcher_add_item(dom_string *data, uint32_t *key);
+nserror html_css_fetcher_add_item(dom_string *data, nsurl *base_url,
+		uint32_t *key);
 
 /* in render/html_object.c */